Articulating support arm with improved tilter and friction joint

ABSTRACT

The present application discloses an articulating support arm with improved friction joint designs that are facilitated by the use of a non-annular bushing. In particular, the bushing is designed to interact with another portion of the friction joint to prevent rotational movement of the bushing, thereby minimizing the risk of joint malfunction. A bushing that interacts with a larger percentage of the width of a friction cylinder as compared to prior art devices, thereby improving the performance of the joint, is also disclosed. The improved friction joint according to the present invention may comprise an arm joint and/or tilter joint.

FIELD OF THE INVENTION

The present invention relates to an articulating support arm having atilter assembly for positioning an attached user device, for example anelectronic device such as a flat-screen monitor.

BACKGROUND OF THE INVENTION

Some existing articulating arm and tilter designs use a set screw thatis driven directly into a bushing of approximately circularcross-sectional area that is positioned around the rotating cylinder ofan arm or tilter joint to supply pressure to the rotating cylinder inorder to restrict rotation of the attached arm or user device about therotating cylinder. In these prior art devices, the bushing includes asplit that permits the size of the outer circumference of the bushing tobe adjusted when acted upon by the set screw, thus supplying the desiredamount of friction to the rotating cylinder. In these devices, properplacement of the split in the bushing away from the axis of the shaft ofthe set screw is necessary to ensure that the bushing properly transfersthe force to the rotating cylinder that is being applied by the setscrew to the bushing. If the split in the bushing becomes alignedwith—or gets too close to being aligned with—the axis of the shaft ofthe set screw, the split in the bushing may not close and open asintended in response to movement of the set screw, thus causing thearticulating arm joint or tilter to malfunction.

Further, in some prior art articulating arms and tilters, the bushingclamps around only a small portion of the width of the rotatingcylinder, which causes clamping forces to be unevenly applied to therotating cylinder and the set screws to work themselves loose over time.

Accordingly, there is a need for an articulating support arm with animproved tilter and friction joint that addresses these and otherdrawbacks of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction withthe appended drawing figures, wherein like numerals denote likeelements.

FIG. 1 is a perspective view of a support arm according to the presentinvention;

FIG. 2 is a perspective top view of the lower arm portion of the supportarm of FIG. 1, with the lower arm portion channel cover removed;

FIG. 3 is a partial exploded view of the lower endcap and lower armportion of the support arm of FIG. 1;

FIG. 4 is a partial exploded view of the lower arm portion of thesupport arm of FIG. 1;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is a partial exploded view of a tilter assembly of the supportarm of FIG. 1;

FIGS. 7 and 8 are partial exploded views of components thereof;

FIG. 9 is a partial exploded view of the tilter assembly of FIG. 6;

FIG. 10 is a sectional view taken along line 10-10 of FIG. 1;

FIG. 11 is a perspective view of a tilter in accordance with the priorart;

FIG. 12 is an exploded view thereof;

FIG. 13 is a perspective view of a tilter in accordance with analternate embodiment of the present invention;

FIG. 14 is a sectional view taken along line 14-14 of FIG. 13; and

FIG. 15 is an exploded view of the tilter of FIG. 13.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The ensuing detailed description provides preferred exemplaryembodiments only, and is not intended to limit the scope, applicability,or configuration of the invention. Rather, the ensuing detaileddescription of the preferred exemplary embodiments will provide thoseskilled in the art with an enabling description for implementing thepreferred exemplary embodiments of the invention. It being understoodthat various changes may be made in the function and arrangement ofelements without departing from the spirit and scope of the invention,as set forth in the appended claims.

To aid in describing the invention, directional terms may be used in thespecification and claims to describe portions of the present invention(e.g., upper, lower, left, right, etc.). These directional definitionsare merely intended to assist in describing and claiming the inventionand are not intended to limit the invention in any way. In addition,reference numerals that are introduced in the specification inassociation with a drawing figure may be repeated in one or moresubsequent figures without additional description in the specificationin order to provide context for other features.

Referring generally to FIGS. 1-10, an embodiment of a support arm 10according to the present invention will be described in detail. As willbe described in detail below, the support arm 10 is fully articulable inall three spatial axes to permit the desired placement and orientationof an attached electronic device (e.g., a display monitor). In thisembodiment, the support arm 10 comprises a support mount 12 that is usedto attach the support arm 10 to a desired surface. In this embodiment,the support mount 12 comprises a C-clamp (not shown) for attaching thesupport arm 10 around the edge of a desk, table top, or other supportsurface. In alternate embodiments, the support mount 12 could comprise abolt-through mount, wall mount, ceiling mount, slat-wall mount, railmount, or any other type of known mounting structure. Referring back tothe embodiment of FIG. 1, the support arm 10 further comprises a baseportion 13 having a cable router 14 attached thereto for collecting androuting cables that extend from the attached device. In this embodiment,the base portion 13 is rotatably coupled to the support mount 12 about agenerally vertical axis (not labeled). In alternate embodimentsaccording to the present invention, the base portion 13 could berotationally fixed with respect to the support mount 12.

In the present embodiment, the support arm 10 further comprises a lowerendcap 16, a lower arm portion 22 that is connected at a first end tothe lower endcap 16 and at a second end to an upper endcap 58, a forearm84 that is connected at a first end to the upper endcap 58 and at asecond end to a tilter assembly 92, and a device mount 88 connected tothe tilter assembly 92 that accommodates mounting an electronic device(e.g., a computer display monitor) thereto. As seen in FIG. 1, the lowerendcap 16 is covered by a channel cover 24 for aesthetic purposes and toeliminate pinch points. In alternate embodiments, the channel cover 24could be omitted. In the embodiment of FIG. 1, a second cable router 62for collecting and routing cables that extend from the attachedelectronic device is attached to the upper endcap 58. In thisembodiment, the bottom side of the forearm 84 is partially hollow tosave on material costs. In alternate embodiments according to thepresent invention, cable clips or tabs could be included within thehollow space on the bottom side of the forearm 84 to permit devicecable(s) to be at least partially retained and concealed within theforearm 84. In further alternate embodiments, the forearm 84 could beomitted entirely from the support arm 10, and the tilter assembly 92 anddevice mount 88 could be attached directly to the upper endcap 58.

FIGS. 2-5 generally show the construction of the lower arm portion 22 ofthe support arm 10. In this embodiment, the lower endcap 16 functions asthe lower joint of a parallelogram structure comprising a lower channel50 and a pair of stringers 56 a,56 b that collectively comprise an upperchannel of the parallelogram structure, and the upper endcap 58functions as the upper joint of the parallelogram structure. Saidanother way, the lower channel 50 is maintained in a parallelrelationship to the pair of stringers 56 a,56 b in all positions andorientations of the lower arm portion 22 via the connections made byeach of the stringers 56 a,56 b and the lower channel 50 with both ofthe lower endcap 16 and upper endcap 58. A first endcap pin 60 arotatably attaches the lower channel 50 to the upper endcap 58 and asecond endcap pin 60 b rotatably attaches the stringers 56 a,56 b to theupper endcap 58. In the present embodiment, each of the endcap pins 60a,60 b is fixed in place by a respective retainer ring (not shown orlabeled) that attaches to the end of the respective endcap pin 60 a,60 band prevents the respective endcap pin 60 a,60 b from sliding out of theupper endcap 58. An axle pin 26 rotatably attaches the lower channel 50to the lower endcap 16 about an axis of rotation 33 (see FIG. 4) and aspring axle pin 34 rotatably attaches the stringers 56 a,56 b to thelower endcap 16.

As shown in FIGS. 2 and 5, the lower arm portion 22 further comprises aspring 38 that is attached between the lower endcap 16 and the lowerchannel 50 and nested above the lower channel 50 and between thestringers 56 a,56 b. In this embodiment, an upper end of the spring 38has a hooked portion 40 that hooks around a hook slot 54 located in thelower channel 50 to fix the upper end of the spring 38 in relation tothe lower channel 50. In this embodiment, the lower end of the spring 38terminates within the length of the lower arm portion 22. A springconnection nut 42 is fixed to the lower end of the spring 38 and aspring connection bolt 46 is attached between the spring axle pin 34 andthe spring connection nut 42. The spring connection nut 42 is internallythreaded and engages with threading on the exterior of the springconnection bolt 46. A retaining ring 44 locks the spring connection bolt46 to the spring connection nut 42. A pair of retaining rings (onlyretaining ring 36 labeled) fix the ends of the spring axle pin 34 to thestringers 56 a,56 b. In alternate embodiments according to the presentinvention, the spring 38 could be connected between the lower endcap 16and the upper channel (via one or both stringers 56 a,56 b).

In this embodiment, the spring connection bolt 46 is used to supply adesired amount of tension to the spring 38 in order to permit the lowerarm portion 22 to support a desired amount of mass that will be attachedto the device mount 88 (e.g., the mass of a computer display monitor).In this embodiment, a bolt head 47 of the spring connection bolt 46 isrotated during construction of the lower arm portion 22 in order to movethe spring connection nut 42 along the length of the spring connectionbolt 46, thereby pre-tensioning the spring 38 to accommodate an attacheddevice mass equal to the minimum end of the range of masses that thesupport arm 10 is designed to support. For example, if the support arm10 is designed to support devices weighing between 6 and 20 pounds, thespring 38 is pre-tensioned during assembly to support (i.e., counteract)a mass of 6 pounds. As explained below in detail, the improved frictionjoint design according to the present invention is used to provide anynecessary additional restorative force to the lower arm portion 22 toaccommodate greater attached weights. In alternate embodiments accordingto the present invention, the bolt head 47 is accessible to the end userafter the support arm 10 has shipped so that the end user can adjust theamount of restorative force that the spring 38 supplies to the lower armportion 22.

As shown in the partial exploded view of FIG. 3, the axle pin 26comprises a head 27, a first locking portion 30, a shaft 28 ofcylindrical shape and having an exterior surface 29, and a secondlocking portion 31. It should be understood that the shaft 28 of theaxle pin 26 acts as a friction cylinder that is engaged by a bushing 70,as will be described below in detail. The lower endcap 16 has an opening18 through which the shaft 28 rotatably extends when the axle pin 26 isinstalled in the lower arm portion 22. The first locking portion 30 hasa non-circular shape and a complementary-shaped locking portion cutout52 is provided on a first side of the bottom end of the lower channel 50so that the first locking portion 30 mates with the locking portioncutout 52 when the axle pin 26 is installed in the lower arm portion 22.The second locking portion 31, which is located on the opposite end ofthe shaft 28, also has a non-circular shape and mates with anon-circular cutout (not shown) located on the second side (not shown)of the bottom end of the lower channel 50 when the axle pin 26 isinstalled in the lower arm portion 22. In this way, the axle pin 26 isfixed to and rotates with the lower channel 50 about the axis ofrotation 33 as the position of the lower arm portion 22 is changed.Simultaneously, the shaft 28 of the axle pin 26—due to its cylindricalshape—rotates within the opening 18 in the lower endcap 16.

As noted above, in this embodiment the lower endcap 16 comprises afriction joint in which the axle pin 26 serves as a friction cylinder,in other words a cylinder that is acted on by frictional forces in orderto retard the movement of an object—in this case the lower channel 50—towhich the axle pin 26 is attached. In this embodiment, the bottom sideof the lower endcap 16 comprises a threaded passage 20. A threadedmember 64, which in this embodiment is a set screw having a head 65, athreaded shaft 66, and an end face 67, is inserted into the threadedpassage 20 and extended into or retracted from the threaded passage 20to a desired degree by the end user of the support arm 10 in order toimpart a desired amount of force to an exterior surface 75 of thebushing 70, as will be discussed below in greater detail. The threadedshaft 66 of the threaded member 64 is linear and has a central axis 68.In this embodiment, the threaded member 64 has a hex head opening thatrequires an Allen wrench or similar tool to adjust the tightness of thethreaded member 64 against the bushing 70. In alternate embodiments, thethreaded member 64 could be replaced with a manually-adjustable knobthat does not require a tool to operate.

In the present embodiment, the bushing 70 is located within the opening18 in the lower endcap 16 and the exterior surface 75 of the bushing 70is in contact with the interior surfaces of the opening 18. The bushing70 comprises a main portion 72 having an outer circumference 73 (seeFIG. 5), a first tab 78 that extends partially exterior to the outercircumference 73 of the main portion 72, and a second tab 80 thatextends partially exterior to the outer circumference 73 of the mainportion 72. A split 76 is located between the first tab 78 and thesecond tab 80, and extends partially exterior to the outer circumference73. An outer surface 79 of the first tab 78 rests against a firstseating surface (not labeled) of the opening 18 of the lower endcap 16,and an outer surface 81 of the second tab 80 rests against a secondseating surface 19 of the opening 18 of the lower endcap 16. In thisembodiment, the threaded passage 20 extends through the bottom surfaceof the lower endcap 16 and terminates on the first seating surface ofthe opening 18. In alternate embodiments according to the presentinvention, the threaded passage 20 could extend through the top surfaceof the lower endcap 16 and terminate on the second seating surface 19 ofthe opening 18. In this embodiment, the first tab 78 and second tab 80of the bushing 70 are identical in shape and size. In alternateembodiments, the first tab 78 and second tab 80 could be of differentshapes and/or sizes.

In this embodiment, when the threaded member 64 is extended further intothe opening 18, an increased amount of force is imparted to the outersurface 79 of the first tab 78. Because the second tab 80 is in contactwith the second seating surface 19 and the bushing 70 is otherwisecaptive within the opening 18, the split 76 of the bushing 70 ismaintained in its desired non-aligned orientation with respect to thecentral axis 68 of the threaded shaft 66 of the threaded member 64. Thisgreatly reduces the likelihood that the bushing 70 will becomemisaligned over time as compared to known prior art devices.Furthermore, imparting force to or withdrawing force from the outersurface 79 of the first tab 78 will cause the outer circumference 73 ofthe bushing 70 to change in size. For example, when an increased amountof force is imparted to the outer surface 79 of the first tab 78 byrotating the threaded member 64 such that it extends further into theopening 18, the size of the split 76 decreases, thus reducing the sizeof the outer circumference 73. The bushing 70 further comprises aninterior surface 74 that engages the exterior surface 29 of the axle pin26, which is routed interior to the bushing 70.

In alternate embodiments according to the present invention, thefriction joint described above could be located instead within the upperendcap 58, with the spring 38 connected between the upper endcap 58 andeither of the lower channel 50 or the upper channel (via one or bothstringers 56 a,56 b), with the necessary changes to the arrangement ofthe support arm 10 being made, as would be appreciated by one havingordinary skill in the art.

As would be understood by one having ordinary skill in the art, it isdesirable to design a support arm that is articulable and repositionablesuch that the attached device (e.g., a monitor) stays where it isplaced, for example at different heights and rotational positions toaccommodate different users of a workstation. Therefore, it is desirablethat the restorative force applied by the support arm 10 to the devicemount 88 at least approximates—and most desirably closely matches—themass of the attached device, so that the attached device doesn't either“float up” or fall down after it has been placed in a desired position.As noted above, the spring 38 provides a baseline amount of restorativeforce to the lower arm portion 22, and thus to the entire support arm10. Adjusting the position of the threaded member 64 with respect to thefirst tab 78 of the bushing 70 acts to increase or decrease the amountof frictional force that the interior surface 74 of the bushing 70applies to the exterior surface 29 of the shaft 28 of the axle pin 26.Because the axle pin 26 is fixed to the lower channel 50 of the lowerarm portion 22 via the first locking portion 30 and second lockingportion 31, the addition of friction to the shaft 28 of the axle pin 26permits the lower arm portion 22 (and accordingly the entire support arm10) to support a greater attached mass from the device mount 88 in astable (i.e., counterbalanced) position. Conversely, a reduction in theamount of force that is being applied to the shaft 28 of the axle pin 26by the bushing 70 reduces the mass that will be supported (i.e.,counterbalanced) by the lower arm portion 22. In practice, a user wouldlikely make fine adjustments of the position of the threaded member 64until the supporting force of the lower arm portion 22 (which isapproximately equal to the restorative force supplied by the spring 38to the lower channel 50 and the frictional force supplied to the lowerchannel 50 via the axle pin 26 being acted on by the bushing 70)approximately matches the gravitational forces that are pullingdownwardly on the support arm 10 and any attached device.

In this embodiment, the central axis 68 of the threaded shaft 66 of thethreaded member 64 that comes into contact with the first tab 78 of thebushing 70 does not intersect with any portion of the outercircumference 73 of the main portion 72 of the bushing 70. In otherwords, the location at which pressure is applied to the first tab 78 ofthe bushing 70 to grip the bushing 70 around the shaft 28 of the axlepin 26 is offset from the main portion 72 of the bushing 70. Thisgeometry, coupled with the presence of the first seating surface andsecond seating surface 19—which act to hold the non-annular bushing 70in a preferred rotational orientation with respect to the threadedmember 64—allows for much finer, more accurate, and more reliableadjustment of the friction that is applied to the axle pin 26 by thebushing 70 as compared to known prior art devices. In alternateembodiments, the central axis 68 of the threaded shaft 66 of thethreaded member 64 could intersect with or even bisect the main portion72 of the bushing 70, so long as the end face 67 of the threaded member64 engages the first tab 78 or second tab 80 at an angle sufficient toadequately alter the size of the split 76 in the bushing 70 to properlyvary the amount of friction being applied to the shaft 28 of the axlepin 26. Turning back to the present embodiment, the central axis 68 isoriented at an orthogonal angle to the split 76 in the bushing 70 whenthe threaded shaft 66 is extended through the threaded passage 20. Inalternate embodiments, the central axis 68 could be arranged at anon-orthogonal angle with respect to the split 76 when the threadedshaft 66 is extended through the threaded passage 20. For example, thecentral axis 68 could be arranged with respect to the split 76 at anangle between 0-90 degrees, more preferably at an angle between 15-90degrees, and most preferably at an angle between 30-90 degrees.

As shown in FIG. 5, forearm 84 is attached to upper endcap 58 such thatthe forearm 84 may rotate about a vertical axis with respect to theupper endcap 58. In this embodiment, the forearm 84 is attached to theupper endcap 58 via a structure that is identical to the structure thatis employed to connect the forearm 84 to the tilter assembly 92. Thisstructure will be discussed in greater detail below with respect to FIG.10, it being understood that this discussion is equally applicable tothe connection between the forearm 84 and the upper endcap 58.

Referring now to FIGS. 6-10, a first embodiment of a tilter assembly 92according to the present invention will be described in detail. In thisembodiment, the tilter assembly 92 comprises the device mount 88, whichin this embodiment comprises two sets of four display screen mountingholes (not labeled) that are arranged according to existing industrystandards for video displays, for example the Video ElectronicsStandards Association (VESA). In this embodiment, the two sets ofdisplay screen mounting holes are arranged, respectively, in 75 mm×75 mmand 100 mm×100 mm square hole patterns according to VESA standards. Itshould be understood that, in alternate embodiments, the display screenmounting holes may be arranged in non-standard pattern(s), only one setof display screen mounting holes may be included on the device mount 88,or more than two sets of display screen mounting holes may be includedon the device mount 88. As would be appreciated by one having ordinaryskill in the relevant art, an electronic device (e.g., a monitor) ismountable to the device mount 88 by aligning the appropriate set ofdisplay screen mounting holes with the appropriate mounting holes on theback of the electronic device, and securing appropriate fasteners (e.g.,machine screws) through both sets of holes.

In this embodiment, the tilter assembly 92 further comprises a tilterbody 94 that is rotatably attached to a coupling 86 of the forearm 84about a generally vertical axis (not labeled) and a center tilt mount110 that is rotatably attached to the tilter body 94 via a frictioncylinder 160 about an axis of rotation 165. The tilter assembly 92further comprises a rivet plate 122 and a rivet plate holder 142. Therivet plate 122 comprises a main body 126 having a top edge 127, a frontside 124 that includes a front mount portion 128 and a mounting shaft130 having a rivet hole 132 centrally located therein, and a rear side134 that includes a sloped surface 136 at its lower end. In thisembodiment, the device mount 88 is mounted to the rivet plate 122 byrouting a rivet (not shown) sequentially through washer 138 b, washer140 b, a central mounting hole 89 of the device mount 88, washer 140 a,washer 138 a, and into the rivet hole 132 of the rivet plate 122. Inthis embodiment, the washers 138 a,138 b are comprised of steel forrigidity and the washers 140 a,140 b are comprised of nylon so thatthere is no metal-on-metal contact after the device mount 88 is mountedinto the rivet hole 132 of the mounting shaft 130. It should beunderstood that, in alternate embodiments, suitable alternate materialsfor the washers 138 a,138 b,140 a,140 b are possible within the scope ofthis invention. In this embodiment, the device mount 88 is rotatable in360 degrees with respect to the mounting shaft 130 once attachedthereto. In alternate embodiments, the device mount 88 may berotationally fixed with respect to the mounting shaft 130 or rotatableonly through a particular range of motion through the use of one or morestop members (e.g., rotatable by a maximum of approximately 90 degreesto permit an attached electronic display to be reoriented only betweenportrait and landscape orientations).

The rivet plate holder 142 comprises a main portion 143 and a mountingportion 152. A front side 144 of the main portion 143 comprises arelease tab 146, a catch 148 having a sloped surface 149, and a stud150. A rear side 154 of the main portion 143 comprises a mounting hook156 located at a bottom end thereof. The center tilt mount 110 comprisesa front mount cutout 112 that permits the mounting shaft 130 of therivet plate 122 to extend from the center tilt mount 110 once the rivetplate 122 is installed within the center tilt mount 110, and an arcuateportion 114 that accommodates the plate-shaped rear indentation (seeFIG. 6) of the device mount 88.

As seen in FIG. 8, the center tilt mount 110 comprises a rivet plateholder slot 118 for releasably supporting the rivet plate holder 142therein and a rivet plate slot 116 for releasably supporting the rivetplate 122 therein. When the rivet plate holder 142 is installed withinthe rivet plate holder slot 118 of the center tilt mount 110, themounting portion 152 of the rivet plate holder 142 engages the slottedside portions of the rivet plate holder slot 118 and the mounting hook156 located on the bottom end of the rivet plate holder 142 engages amounting hook slot 120 that is formed through a bottom surface 96 of thecenter tilt mount 110. In this way, the rivet plate holder 142 issecurely but releasably installed within the center tilt mount 110. Ifnecessary, the rivet plate holder 142 may be released from the centertilt mount 110 by pressing forwardly on the mounting hook 156 whilepulling upwardly on the rivet plate holder 142, thereby freeing themounting hook 156 from the mounting hook slot 120 and permitting therivet plate holder 142 to be pulled upwardly out of the rivet plateholder slot 118 and removed from the center tilt mount 110.

In this embodiment, the rivet plate 122 is releasably attachable to therivet plate holder 142. Specifically, when the rivet plate 122 is moveddownwardly towards the rivet plate holder 142 to install the rivet plate122—as partially shown in FIG. 7—the sloped surface 136 of the rear side134 of the main body 126 of the rivet plate 122 rides along the catch148 and temporarily deforms the main portion 143 of the rivet plateholder 142 rearwardly until the top edge 127 of the main body 126 of therivet plate 122 clears the sloped surface 149 of the catch 148. Once thetop edge 127 of the main body 126 of the rivet plate 122 clears thesloped surface 149 of the catch 148 of the rivet plate holder 142, themain portion 143 of the rivet plate holder 142 will inherently springback forwardly so that the catch 148 becomes located above the top edge127 of the main body 126 of the rivet plate 122 as the rivet plate 122slides into the rivet plate slot 116. The rivet plate 122 is thussecurely but releasably installed within the tilter assembly 92. Torelease the rivet plate 122 (and any attached device) from the tilterassembly 92, a user would deform the main portion 143 of the rivet plateholder 142 by pressing rearwardly on the release tab 146 until the catch148 is no longer located above the top edge 127 of the main body 126 ofthe rivet plate 122 while simultaneously lifting upwardly on the rivetplate 122 (and any attached device) until the top edge 127 of the rivetplate 122 is clear of the catch 148. The tilter assembly 92 according tothe present invention thus provides an improved quick-release mechanismover prior art devices. In this embodiment, the main body 126 of therivet plate 122 has a generally keystone-shaped profile that greatlyreduces the risk that a user will install the rivet plate 122incorrectly into the center tilt mount 110. Not only does the irregularshape of the main body 126 of the rivet plate 122 visually indicate tothe user the appropriate orientation of the rivet plate 122, but therivet plate 122 will in general attach easily to the tilter assembly 92only when the sloped surface 136 is aimed downwardly duringinstallation.

FIGS. 9 and 10 show additional details of the tilter assembly 92. Inthis embodiment, the tilter assembly 92 has a tilter body 94 having anopening 100 therethrough, a bottom surface 96, a top surface 97, athreaded passage 106 extending through the bottom surface 96 and intothe opening 100, and a tilter shaft 98 extending from the bottom surface96 which is used to attach the tilter assembly 92 to the coupling 86 ofthe forearm 84 and rotate the tilter assembly 92 about a generallyvertical axis (not labeled). A bearing bushing 83 of generally circularshape is located between the tilter body 94 and the coupling 86 of theforearm 84 to prevent metal-on-metal contact between the tilter body 94and coupling 86. As noted above, the connection between the forearm 84and the tilter assembly 92 comprises an anti-loosening apparatus thatprevents the tilter assembly 92 from coming loose from the coupling 86of the forearm 84 as the tilter shaft 98 is rotated with respect to thecoupling 86. In this embodiment, the bottom end of the tilter shaft 98is circular except for a cutout portion 99. A bearing washer 85 ofgenerally circular shape is located between the coupling 86 of theforearm 84 and a shaft cap 87. In this embodiment the bearing washer 85is comprised of steel, but in alternate embodiments according to thepresent invention suitable additional materials are possible, forexample nylon or acetal resin. The shaft cap 87 is generally annular inshape, but also has a protruding portion 91 that protrudes inwardly fromthe interior surface and mates with the cutout portion 99 of the bottomend of the tilter shaft 98. A fastener 93 is routed through the shaftcap 87 and rotated into threading located in the bottom end of thetilter shaft 98 to secure the joint together. Due to the interactionbetween the protruding portion 91 of the shaft cap 87 and the cutoutportion 99 of the bottom end of the tilter shaft 98, the tilter shaft 98and shaft cap 87 are rotationally fixed together below the coupling 86,thus preventing this joint from coming loose over time. In alternateembodiments according to the present invention, the bottom end of thetilter shaft 98 contains a plurality of cutout portions or indents andthe shaft cap 87 comprises a complementary plurality of protrusions thatmate with the cutout portions in the tilter shaft 98 such that thetilter shaft 98 and shaft cap 87 are rotationally fixed together.

A threaded member 186, which in this embodiment is a set screw having ahead 187, a threaded shaft 188, and an end face 189, is inserted intothe threaded passage 106 and extended into or retracted from the opening100 to a desired degree in order to impart a desired amount of force toan exterior surface 174 of a bushing 166, as will be discussed below infurther detail. The threaded shaft 188 of the threaded member 186 has acentral axis 190. In this embodiment, the threaded member 186 willtypically be rotated using a tool (e.g., an Allen wrench) to adjust thetightness of the threaded member 186 against the bushing 166. Inalternate embodiments, the set screw could be replaced with a bolt orother fastener that requires a tool to operate or a manually-adjustableknob.

The opening 100 in the tilter body 94 has a width 101 and contains afirst seating surface 102 and a second seating surface 104. The bushing166 is located within the opening 100 and the exterior surface 174 ofthe bushing 166 is in contact with the interior surfaces of the opening100. The bushing 166 comprises a main portion 168 having a width 167 andan outer circumference 170, a first tab 178 that extends partiallyexterior to the outer circumference 170 of the main portion 168, and asecond tab 182 that extends partially exterior to the outercircumference 170 of the main portion 168. A split 176 is locatedbetween the first tab 178 and the second tab 182, and the split 176extends partially exterior to the outer circumference 170. An outersurface 180 of the first tab 178 rests against the first seating surface102 and an outer surface 184 of the second tab 182 rests against thesecond seating surface 104. In this embodiment, the threaded passage 106extends through the bottom surface 96 of the tilter body 94 andterminates on the first seating surface 102. In alternate embodimentsaccording to the present invention, the threaded passage 106 couldextend through the top surface of the tilter body 94 and terminate onthe second seating surface 104. In the present embodiment, the first tab178 and second tab 182 are of different shapes. In alternateembodiments, the first tab 178 and second tab 182 could be of the sameshape and/or size.

In the present embodiment, when the threaded member 186 is extendedfurther into the opening 100, an increased amount of force is impartedto the outer surface 180 of the first tab 178. Because the second tab182 is in contact with the second seating surface 104 and the bushing166 is otherwise captive within the opening 100, the split 176 of thebushing 166 is maintained in its desired non-aligned orientation withrespect to the central axis 190 of the threaded shaft 188 of thethreaded member 186. This greatly reduces the likelihood that thebushing 166 will become misaligned over time as compared to known priorart tilters. In this way, imparting force to or withdrawing force fromthe outer surface 180 of the first tab 178 will cause the outercircumference 170 to change in size. For example, when an increasedamount of force is imparted to the outer surface 180 of the first tab178 by rotating the threaded member 186 such that it extends furtherinto the opening 100, the size of the split 176 decreases, thus reducingthe size of the outer circumference 170. The bushing 166 furthercomprises an interior surface 172 that engages an exterior surface 164of a friction cylinder 160 that is routed interior to the bushing 166.

In this embodiment, the friction cylinder 160 has a width 161 and aknurled end portion 162 that fixedly engages the center tilt mount 110such that the friction cylinder 160 and center tilt mount 110 rotatesimultaneously about the axis of rotation 165. As noted above, a userdevice having a particular mass is attached to the device mount 88—whichis fixedly attached to the center tilt mount 110—and the threaded member186 is tightened against the outer surface 180 of the first tab 178until sufficient force is applied to the friction cylinder 160 by thebushing 166 to adequately support the mass of the user device.

In this embodiment, the central axis 190 of the threaded shaft 188 ofthe threaded member 186 that comes into contact with the first tab 178of the bushing 166 intersects the outer circumference 170 of the mainportion 168 of the bushing 166 and the end face 189 of the threadedmember 186 engages the first tab 178 at an angle sufficient toadequately alter the size of the split 176 in the bushing 166 toproperly vary the amount of friction being applied to the frictioncylinder 160. In alternate embodiments, the central axis 190 couldintersect the outer circumference 170 at any possible angle, includingbisecting the outer circumference 170, or could not intersect with theouter circumference 170 at all, so long as the end face 189 of thethreaded member 186 engages the first tab 178 at an angle sufficient toadequately alter the size of the split 176 in the bushing 166 toproperly vary the amount of friction being applied to the frictioncylinder 160. In the present embodiment, the central axis 190 isoriented at a non-orthogonal angle of approximately 40 degrees to thesplit 176 in the bushing 166 when the threaded shaft 188 is extendedthrough the threaded passage 106. In alternate embodiments, the centralaxis 190 could be arranged at an orthogonal angle or othernon-orthogonal angles with respect to the split 176 when the threadedshaft 188 is extended through the threaded passage 106. For example, thecentral axis 190 could be arranged with respect to the split 176 at anyangle between 0-90 degrees, more preferably at an angle between 15-90degrees, and most preferably at an angle between 30-90 degrees.

In this embodiment, the bushing 166 has a width 167 that is much largerin comparison to both the width 101 of the opening 100 in the tilterbody 94 and the width 161 of the friction cylinder 160 than therespective width ratios in the tilter assembly 210 according to theprior art that is shown in FIGS. 11 and 12 and discussed below. Forexample, in this embodiment the width 167 of the bushing 166 is greaterthan 50% of the width 161 of the friction cylinder 160 and equal to thewidth 101 of the opening 100 in the tilter body 94. In alternateembodiments, the width 167 of the bushing 166 may be between 50-90% ofthe width 161 of the friction cylinder 160 and/or the width 167 of thebushing 166 may be between 75-100% of the width 101 of the opening 100in the tilter body 94. In further alternate embodiments, the width 167of the bushing 166 may be approximately two-thirds of the width 161 ofthe friction cylinder 160 and/or the width 167 of the bushing 166 may beapproximately equal to the width 101 of the opening 100 in the tilterbody 94.

For sake of comparison, FIGS. 11 and 12 show a tilter assembly 210 inaccordance with the prior art. For ease of discussion certain primarycomponents of the tilter assembly 210 are omitted from these figures,for example the center tilt mount that attaches to the ends of thefriction cylinder 240 and that is used to support a user device, forexample a flat-screen monitor. As shown in FIGS. 11 and 12, the tilterassembly 210 comprises a tilter body 212 having an opening 214therethrough, the opening 214 having a width 217. The tilter body 212further comprises a bottom surface 216, a top surface 218, a passage 220extending through the bottom surface 216 and into the opening 214, and atilter shaft 226 extending from the bottom surface 216 which is used toattach the tilter assembly 210 to a support means and rotate the tilterassembly 210 about a generally vertical axis (not labeled). The passage220 is internally threaded.

A threaded member 230, which in this embodiment is a set screw having ahead 232, a threaded shaft 234, and an end face 238, is inserted intothe passage 220 and extended into or retracted from the opening 214 to adesired degree in order to impart a desired amount of force to anexterior surface 258 of a bushing 250, as will be discussed below ingreater detail.

The bushing 250 is located within the opening 214 and the exteriorsurface 258 of the bushing 250 is in contact with the interior surfacesof the opening 214. The bushing 250 comprises a split 262 along itscircumference. The bushing 250 has an outer circumference 254 thatchanges in size when the amount of force imparted to the exteriorsurface 258 thereof by the threaded member 230 is adjusted. For example,when an increased amount of force is imparted to the exterior surface258 of the bushing 250 by rotating the threaded member 230 such that itextends further into the opening 214, the size of the split 262decreases so that the outer circumference 254 decreases in size, becausethe bushing 250 is captive within the opening 214 such that the bushing250 cannot otherwise move. The bushing 250 further comprises an interiorsurface 256 that engages an exterior surface 244 of a friction cylinder240 that is routed interior to the bushing 250 along an axis of rotation215. The bushing 250 has a width 260 and the friction cylinder has awidth 246.

In this prior art tilter assembly 210, the friction cylinder 240comprises a knurled end portion 242 that fixedly engages a center tiltmount component (not shown) such that the friction cylinder 240 andcenter tilt mount rotate simultaneously about the axis of rotation 215.As noted above, a user device having a particular mass is attached tothe center tilt mount via one or more intermediate components that wouldbe understood by one having ordinary skill in the art (e.g., a rotatingplate, a VESA plate, and/or a quick-release adapter). In order to handlea device having a large mass, the threaded member 230 is pressed moretightly into the exterior surface 258 of the bushing 250, therebyimparting a greater frictional force to the exterior surface 244 of thefriction cylinder 240 until the mass of the user device is appropriatelysupported. An item of lesser mass would not require the threaded member230 to be pressed as tightly into the bushing 250.

In this prior art tilter assembly 210, the width 260 of the bushing 250is approximately 50% of the width 217 of the opening 214 in the tilterbody 212, and the width 260 of the bushing 250 is approximately 25-30%of the width 246 of the friction cylinder 240. Accordingly, whenpressure is applied to the exterior surface 258 of the bushing 250, theinterior surface 256 of the bushing 250 applies force to less thanone-third of the width 246 of the friction cylinder 240. This can causethe forces to be applied unevenly to the friction cylinder 240, andresult in the threaded member 230 working itself loose over time as theuser device is moved (i.e., cycled) up and down about the axis ofrotation 215. Moreover, in the prior art tilter assembly 210 the bushing250 is made of bronze, which is expensive and causes the tilter assembly210 to create creaking noises when metal-on-metal contact between thethreaded member 230 and the bushing 250 occurs.

Further, in the prior art tilter assembly 210, if the bushing 250 isinstalled improperly such that the end face 238 of the threaded member230 engages the split 262 in the bushing 250 or the split 262 is notproperly rotated with respect to the threaded member 230 such that theforce imparted by the threaded member 230 will act to change the size ofthe split 262 (for example if the split 262 is rotated exactly oppositethe location where the end face 238 engages the bushing 250), the tilterassembly 210 will malfunction. Because the bushing 250 is annular,furthermore, there is nothing to prevent the bushing 250 from rotatingout of its desired orientation with respect to the threaded member 230over time if the frictional forces being applied to the bushing 250become insufficient to prevent its rotation.

Referring now to FIGS. 13-15, an alternate embodiment of a tilterassembly 310 according to the present invention will be described indetail. In this embodiment, the tilter assembly 310 has a tilter body312 having an opening 314 therethrough, a bottom surface 316, a topsurface 318, a passage 320 extending through the top surface 318 andinto the opening 314, and a tilter shaft 326 extending from the bottomsurface 316 which is used to attach the tilter assembly 310 to a supportmeans and rotate the tilter assembly 310 about a generally verticalaxis. In this embodiment, the passage 320 has internal threading. Theopening 314 has a width 317 (see FIG. 15) and contains a first seatingsurface 322 and a second seating surface 324. In this embodiment, acenter tilt mount 328 of the tilter assembly 310 is shown in FIGS. 13and 14, but is omitted from FIG. 15 for ease of discussion. The centertilt mount 328 attaches to the tilter assembly 310 and functions in thesame manner as in the tilter assembly 92 of FIGS. 6-10.

A threaded member 330, which in this embodiment is an adjustment knobhaving a head 332, a threaded shaft 334, and an end face 338, isinserted into the passage 320 and extended into or retracted from theopening 314 to a desired degree in order to impart a desired amount offorce to an exterior surface 358 of a bushing 350, as will be discussedbelow in greater detail. The threaded shaft 334 of the threaded member330 is linear and has a central axis 336. In this embodiment, thethreaded member 330 may be operated by hand using the head 332 withoutthe need for a tool (e.g., an Allen wrench) to adjust the tightness ofthe threaded member 330 against the bushing 350. In alternateembodiments, the adjustment knob could be replaced with a set screw,bolt, or other fastener that requires a tool to operate.

The bushing 350 is located within the opening 314 and the exteriorsurface 358 of the bushing 350 is in contact with the interior surfacesof the opening 314. The bushing 350 comprises a main portion 352 havingan outer circumference 354, a first tab 364 that extends exterior to theouter circumference 354 of the main portion 352, and a second tab 368that extends exterior to the outer circumference 354 of the main portion352. A split 362 is located between the first tab 364 and the second tab368, and extends partially exterior to the outer circumference 354. Anouter surface 366 of the first tab 364 rests against the first seatingsurface 322 and an outer surface 370 of the second tab 368 rests againstthe second seating surface 324. In this embodiment, the passage 320extends through the top surface 318 of the tilter body 312 andterminates on the first seating surface 322. In alternate embodimentsaccording to the present invention, the passage 320 could extend throughthe bottom surface 316 of the tilter body 312 and terminate on thesecond seating surface 324. In this embodiment, the first tab 364 andsecond tab 368 are identical in shape and size. In alternateembodiments, the first tab 364 and second tab 368 could be of differentshapes and/or sizes.

In this embodiment, when the threaded member 330 is extended furtherinto the opening 314, an increased amount of force is imparted to theouter surface 366 of the first tab 364. Because the second tab 368 is incontact with the second seating surface 324 and the bushing 350 isotherwise captive within the opening 314, the bushing 350 is maintainedin its desired non-aligned orientation with respect to the central axis336 of the threaded shaft 334 of the threaded member 330. Furthermore,imparting force to or withdrawing force from the outer surface 366 ofthe first tab 364 will cause the outer circumference 354 to change insize. For example, when an increased amount of force is imparted to theouter surface 366 of the first tab 364 by rotating the threaded member330 such that it extends further into the opening 314, the size of thesplit 362 decreases, thus reducing the size of the outer circumference354. The bushing 350 further comprises an interior surface 356 thatengages an exterior surface 344 of a friction cylinder 340 that isrouted interior to the bushing 350 along an axis of rotation 315.

In this embodiment, the friction cylinder 340 comprises a knurled endportion 342 that fixedly engages the center tilt mount 328 such that thefriction cylinder 340 and center tilt mount 328 are collectivelyrotatable about the axis of rotation 315. As noted above, a user devicehaving a particular mass is attached to the center tilt mount 328, andthe threaded member 330 is tightened against the outer surface 366 ofthe first tab 364 until a sufficient amount of force is applied to thefriction cylinder 340 by the bushing 350 to adequately support the massof the user device.

In this embodiment, the central axis 336 of the threaded shaft 334 ofthe threaded member 330 that comes into contact with the first tab 364of the bushing 350 does not intersect with any portion of the outercircumference 354 of the main portion 352 of the bushing 350. In otherwords, the location at which pressure is applied to the first tab 364 ofthe bushing 350 to grip the bushing 350 around the friction cylinder 340is offset from the main portion 352 of the bushing 350. This geometry,coupled with the presence of the first seating surface 322 and secondseating surface 324 which act to hold the non-annular bushing 350 in apreferred rotational orientation with respect to the threaded member330, allows for much finer, more accurate, and more reliable adjustmentof the friction that is applied to the friction cylinder 340 by thebushing 350. In alternate embodiments, the central axis 336 of thethreaded shaft 334 could intersect with or even bisect the main portion352 of the bushing 350, so long as the end face 338 of the threadedmember 330 engages the first tab 364 or second tab 368 at an anglesufficient to adequately alter the size of the split 362 in the bushing350 to properly vary the amount of friction being applied to thefriction cylinder 340. In the present embodiment, the central axis 336is oriented at an orthogonal angle to the split 362 in the bushing 350when the threaded shaft 334 is extended through the passage 320. Inalternate embodiments, the central axis 336 could be arranged at anon-orthogonal angle with respect to the split 362 when the threadedshaft 334 is extended through the passage 320. For example, the centralaxis 336 could be arranged with respect to the split 362 at an anglebetween 0-90 degrees, more preferably at an angle between 15-90 degrees,and most preferably at an angle between 30-90 degrees.

In this embodiment, the bushing 350 has a width 360 that is much largerin comparison to both the width 317 of the opening 314 and a width 346of the friction cylinder 340 than the respective width ratios in thetilter assembly 210 according to the prior art. For example, in thisembodiment the width 360 of the bushing 350 is greater than 50% of thewidth 346 of the friction cylinder 340 and equal to the width 317 of theopening 314. In alternate embodiments, the width 360 of the bushing 350may be between 50-90% of the width 346 of the friction cylinder 340and/or the width 360 of the bushing 350 may be between 75-100% of thewidth 317 of the opening 314 in the tilter body 312.

The inventors of the present application have discovered that designingbushings so that they contact a larger percentage of the width of thefriction cylinder permits materials other than metals to be used toconstruct the bushing, for example thermoplastics and nylon, resultingin large cost savings and quieter joint operation. In the embodimentsshown in FIGS. 1-10 and 13-15, the bushings 70,166,350 are formed of apolyoxymethylene acetal polymer, which is sold by different companies invarious formulations as either a homopolymer or copolymer, for exampleunder the name Delrin® by E. I. du Pont de Nemours and Company ofWilmington, Del., U.S.A. In alternate embodiments according to thepresent invention, suitable metal bushings could also be used.

The inventors have also discovered that the use of an elongated bushing70,166,350 resulted in frictional forces being much more evenly providedby the bushing 70,166,350 along the width of the friction cylinders28,160,340, leading to much quieter operation and greatly improved wearperformance without any reduction in maximum weight capacity of thedevice. In accordance with the present invention, the width of therespective bushing 70,166,350 is preferably at least 75% of the width ofthe respective opening 18,100,314 in the lower endcap 16 or tilter body94,312, is more preferably at least 90% of the width of the respectiveopening 18,100,314 in the lower endcap 16 or tilter body 94,312, andmost preferably is equal to the width of the opening 18,100,314 in thelower endcap 16 or tilter body 94,312. Further, in accordance with thepresent invention, the width of the respective bushing 70,166,350 ispreferably at least 50% of a width of the respective friction cylinder28,160,340, more preferably approximately 66.7% of a width of therespective friction cylinder 28,160,340, and most preferably at least75% of the width of the respective friction cylinder 28,160,340.

The inventors have also discovered that providing bushings 70,166,350that are not circular in cross section allows for the rotationalorientation of the bushings 70,166,350 to be fixed with respect to therespective threaded member 64,186 or adjustment knob 330, thuspreventing the split 76,176,362 of the respective bushing 70,166,350from rotating out of a desirable non-aligned orientation with respect tothe threaded member 64,186 or adjustment knob 330. This also greatlyreduces the likelihood of joint failure over time and improves thefunctioning of the joint by ensuring that movement of the respectivethreaded member 64,186 or adjustment knob 330 always acts to adjust thesize of the respective split 76,176,362 of the bushings 70,166,350.

While the principles of the invention have been described above inconnection with preferred embodiments, it is to be clearly understoodthat this description is made only by way of example and not as alimitation of the scope of the invention.

FURTHER ASPECTS OF THE INVENTION

Further aspects of the invention include:

Aspect 1. A support arm for supporting an electronic device, the supportarm comprising: a base portion that is adapted to support the supportarm from a mounting surface; a lower arm portion comprising aparallelogram portion, the parallelogram portion comprising an upperchannel, a lower channel, a lower endcap, and an upper endcap, wherein afirst end of the upper channel and a first end of the lower channel areeach rotatably attached to the lower endcap and a second end of theupper channel and a second end of the lower channel are each rotatablyattached to the upper endcap; a tilter assembly, the tilter assemblycomprising a tilter body, a cylinder, and a center tilt mount that isrotatably attached to the tilter body via the cylinder, the center tiltmount being adapted to support the electronic device therefrom; and atleast one friction joint, the at least one friction joint comprising: abushing comprising a main portion having an exterior surface, aninterior surface, and an outer circumference, the bushing furthercomprising a first tab, a second tab, and a split located between thefirst and second tabs, wherein at least one of the first tab and secondtab extends at least partially exterior to the outer circumference ofthe main portion of the bushing; a friction cylinder comprising anexterior surface and at least one portion that fixedly engages with aseparate component of the support arm; an opening for accommodating thebushing and friction cylinder therein; a threaded passage thatintersects with the opening; and a threaded member that is extendablethrough the threaded passage and into the opening, the bushing beinglocated within the opening such that the exterior surface of the mainportion of the bushing engages the opening, the friction cylinder beinglocated within the opening and routed internal to the bushing such thatthe exterior surface of the friction cylinder engages the interiorsurface of the main portion of the bushing, the friction cylinder beingrotatable along with the separate component of the support arm withinthe opening, the threaded member being extendable into the opening suchthat the threaded member makes contact with one of the first tab and thesecond tab of the bushing, wherein the at least one friction joint islocated within at least one of the lower endcap, upper endcap, andtilter assembly, wherein if the at least one friction joint is locatedwithin either of the lower endcap and upper endcap, the separatecomponent is at least one of the upper channel and lower channel, andwherein if the at least one friction joint is located within the tilterassembly, the opening and threaded passage are located in the tilterbody, the cylinder corresponds with the friction cylinder, and theseparate component is the center tilt mount.

Aspect 2. The support arm of Aspect 1, wherein a first friction joint ofthe at least one friction joint is located within the lower endcap and asecond friction joint of the at least one friction joint is locatedwithin the tilter assembly.

Aspect 3. The support arm of either of Aspect 1 and Aspect 2, whereinthe threaded passage intersects with the opening at an orthogonal anglethereto.

Aspect 4. The support arm of any of Aspects 1-3, wherein at least aportion of each of the first tab and the second tab extend exterior tothe outer circumference of the main portion of the bushing.

Aspect 5. The support arm of any of Aspects 1-4, wherein an entirety ofat least one of the first tab and the second tab extends exterior to theouter circumference of the main portion of the bushing.

Aspect 6. The support arm of any of Aspects 1-5, the opening comprisingat least one seating surface located exterior to the outer circumferenceof the main portion of the bushing, wherein one of the first tab andsecond tab is in contact with the at least one seating surface.

Aspect 7. The support arm of any of Aspects 1-6, the opening comprisinga first seating surface and a second seating surface, the first andsecond seating surfaces located exterior to the outer circumference ofthe main portion of the bushing, wherein the first tab is in contactwith the first seating surface and the second tab is in contact with thesecond seating surface, the interaction of the first tab with the firstseating surface and the interaction of the second tab with the secondseating surface preventing rotation of the bushing within the opening.

Aspect 8. The support arm of any of Aspects 1-7, the threaded membercomprising a shaft having a central axis, wherein the central axis doesnot extend through any portion of the outer circumference of the mainportion of the bushing when the threaded member is extended through thethreaded passage.

Aspect 9. The support arm of any of Aspects 1-8, the threaded membercomprising a shaft having a central axis, wherein the central axis isoriented at an orthogonal angle to the split in the bushing when theshaft is extended through the threaded passage.

Aspect 10. The support arm of any of Aspects 1-9, wherein the first taband the second tab have different dimensions.

Aspect 11. The support arm of any of Aspects 1-10, wherein the bushinghas a width and the opening has a width, and the width of the bushing isat least 75% of the width of the opening.

Aspect 12. The support arm of any of Aspects 1-11, wherein the bushinghas a width and the opening has a width, and the width of the bushing isat least 90% of the width of the opening.

Aspect 13. The support arm of any of Aspects 1-12, wherein the bushinghas a width and the opening has a width, and the width of the bushing isequal to the width of the opening.

Aspect 14. The support arm of any of Aspects 1-13, wherein the bushinghas a width and the friction cylinder has a width, and the width of thebushing is at least 50% of the width of the friction cylinder.

Aspect 15. The support arm of Aspect 14, wherein the opening has a widthand the width of the bushing is at least 75% of the width of theopening.

Aspect 16. The support arm of Aspect 14, wherein the opening has a widthand the width of the bushing is at least 90% of the width of theopening.

Aspect 17. The support arm of Aspect 14, wherein the opening has a widthand the width of the bushing is equal to the width of the opening.

Aspect 18. The support arm of any of Aspects 1-17, wherein the upperchannel comprises a pair of stringers.

Aspect 19. A support arm, the support arm comprising: a base portionthat is adapted to support the support arm from a mounting surface; alower arm portion comprising a parallelogram portion, the parallelogramportion comprising an upper channel, a lower channel, a lower endcap,and an upper endcap, wherein a first end of the upper channel and afirst end of the lower channel are rotatably attached to the lowerendcap and a second end of the upper channel and a second end of thelower channel are rotatably attached to the upper endcap; and a tilterassembly, the tilter assembly comprising a tilter body, a frictioncylinder, a bushing, and a threaded member, the tilter body having anopening and a threaded passage located therein, the threaded passageintersecting with the opening, the friction cylinder extending throughthe opening along an axis of rotation, the friction cylinder having anexterior surface and at least one portion that is engageable with acomponent that can support the electronic device therefrom, the frictioncylinder being rotatable relative to the tilter body about the axis ofrotation, the bushing located between the friction cylinder and theopening of the tilter body, the bushing having a main portion, a firsttab, a second tab, and a split located between the first and secondtabs, the main portion having an exterior surface that engages theopening in the tilter body, an interior surface that engages theexterior surface of the friction cylinder, and an outer circumference,at least one of the first tab and second tab extending at leastpartially exterior to the outer circumference of the main portion of thebushing, the threaded member being extendable through the threadedpassage and into the opening of the tilter body such that the threadedmember contacts one of the first tab and second tab.

Aspect 20. The support arm of Aspect 19, wherein at least a portion ofeach of the first tab and the second tab extend exterior to the outercircumference of the main portion of the bushing.

Aspect 21. The support arm of either of Aspect 19 and Aspect 20, whereinan entirety of at least one of the first tab and the second tab extendsexterior to the outer circumference of the main portion of the bushing.

Aspect 22. The support arm of any of Aspects 19-21, the opening of thetilter body comprising at least one seating surface located exterior tothe outer circumference of the main portion of the bushing, wherein oneof the first tab and second tab is in contact with the at least oneseating surface.

Aspect 23. The support arm of any of Aspects 19-22, the opening of thetilter body comprising a first seating surface and a second seatingsurface, the first and second seating surfaces located exterior to theouter circumference of the main portion of the bushing, wherein thefirst tab is in contact with the first seating surface and the secondtab is in contact with the second seating surface, the interaction ofthe first tab with the first seating surface and the interaction of thesecond tab with the second seating surface preventing rotation of thebushing within the opening.

Aspect 24. The support arm of any of Aspects 19-23, the threaded membercomprising a shaft having a central axis, wherein the central axis doesnot extend through any portion of the outer circumference of the mainportion of the bushing when the threaded member is extended through thethreaded passage.

Aspect 25. The support arm of any of Aspects 19-24, the threaded membercomprising a shaft having a central axis, wherein the central axis isoriented at an orthogonal angle to the split in the bushing when theshaft is extended through the threaded passage.

Aspect 26. The support arm of any of Aspects 19-25, wherein the firsttab and the second tab have different dimensions.

Aspect 27. The support arm of any of Aspects 19-26, wherein thecomponent is a center tilt mount that is fixedly engageable with thefriction cylinder such that the friction cylinder and the center tiltmount are collectively rotatable relative to the tilter body about theaxis of rotation.

Aspect 28. The support arm of any of Aspects 19-27, wherein the bushinghas a width and the opening in the tilter body has a width, and thewidth of the bushing is at least 75% of the width of the opening.

Aspect 29. The support arm of any of Aspects 19-28, wherein the bushinghas a width and the opening in the tilter body has a width, and thewidth of the bushing is at least 90% of the width of the opening.

Aspect 30. The support arm of any of Aspects 19-29, wherein the bushinghas a width and the opening in the tilter body has a width, and thewidth of the bushing is equal to the width of the opening.

Aspect 31. The support arm of any of Aspects 19-30, wherein the bushinghas a width and the friction cylinder has a width, and the width of thebushing is at least 50% of the width of the friction cylinder.

Aspect 32. The support arm of Aspect 31, wherein the opening in thetilter body has a width and the width of the bushing is at least 75% ofthe width of the opening.

Aspect 33. The support arm of Aspect 31, wherein the opening in thetilter body has a width and the width of the bushing is at least 90% ofthe width of the opening.

Aspect 34. The support arm of Aspect 31, wherein the opening in thetilter body has a width and the width of the bushing is equal to thewidth of the opening.

Aspect 35. A support arm, the support arm comprising: a base portionthat is adapted to support the support arm from a mounting surface; alower arm portion comprising a parallelogram portion, the parallelogramportion comprising an upper channel, a lower channel, a lower endcap, anupper endcap, and an extension and retraction device, a first end of theupper channel being rotatably attached to the lower endcap at a firstjoint, a first end of the lower channel being rotatably attached to thelower endcap at a second joint, a second end of the upper channel beingrotatably attached to the upper endcap at a third joint, and a secondend of the lower channel being rotatably attached to the upper endcap ata fourth joint, a first end of the extension and retraction device beingattached to the lower endcap and a second end of the extensionretraction device being attached to the lower channel, wherein at leastone of the first joint and the second joint comprises a friction joint,the lower endcap having a threaded passage therein; and a device mountcoupled to the lower arm portion, the device mount being adapted tosupport an electronic display device therefrom; wherein the frictionjoint comprises an opening located in the lower endcap, a frictioncylinder, a bushing, and a threaded member, the threaded passageintersects with the opening, the friction cylinder extends through theopening along an axis of rotation that corresponds with the respectiveone of the first joint and the second joint, the friction cylinderhaving an exterior surface and at least one portion that is engageablewith the upper channel or lower channel, the friction cylinder beingrotatable relative to the lower endcap about the axis of rotation, thebushing is located between the friction cylinder and the opening, thebushing having a main portion, a first tab, a second tab, and a splitlocated between the first and second tabs, the main portion having anexterior surface that engages the opening in the lower endcap, aninterior surface that engages the exterior surface of the frictioncylinder, and an outer circumference, at least one of the first tab andsecond tab extending at least partially exterior to the outercircumference of the main portion of the bushing, the threaded memberbeing extendable through the threaded passage and into the opening suchthat the threaded member contacts one of the first tab and second tab.

Aspect 36. The support arm of Aspect 35, further comprising a forearm,the forearm being attached at a first end to the upper endcap and at asecond end to the device mount.

Aspect 37. The support arm of either of Aspect 35 and Aspect 36, whereinat least a portion of each of the first tab and the second tab extendexterior to the outer circumference of the main portion of the bushing.

Aspect 38. The support arm of any of Aspects 35-37, wherein an entiretyof at least one of the first tab and the second tab extends exterior tothe outer circumference of the main portion of the bushing.

Aspect 39. The support arm of any of Aspects 35-38, the opening of thetilter body comprising at least one seating surface located exterior tothe outer circumference of the main portion of the bushing, wherein oneof the first tab and second tab is in contact with the at least oneseating surface.

Aspect 40. The support arm of any of Aspects 35-39, the opening of thetilter body comprising a first seating surface and a second seatingsurface, the first and second seating surfaces located exterior to theouter circumference of the main portion of the bushing, wherein thefirst tab is in contact with the first seating surface and the secondtab is in contact with the second seating surface, the interaction ofthe first tab with the first seating surface and the interaction of thesecond tab with the second seating surface preventing rotation of thebushing within the opening.

Aspect 41. The support arm of any of Aspects 35-40, the threaded membercomprising a shaft having a central axis, wherein the central axis doesnot extend through any portion of the outer circumference of the mainportion of the bushing when the threaded member is extended through thethreaded passage.

Aspect 42. The support arm of any of Aspects 35-41, the threaded membercomprising a shaft having a central axis, wherein the central axis isoriented at an orthogonal angle to the split in the bushing when theshaft is extended through the threaded passage.

Aspect 43. The support arm of any of Aspects 35-42, wherein the firsttab and the second tab have different dimensions.

Aspect 44. A tilter for supporting an electronic device, the tiltercomprising: a tilter body, the tilter body having an opening and athreaded passage located therein, the threaded passage intersecting withthe opening; a friction cylinder extending through the opening along anaxis of rotation, the friction cylinder having an exterior surface andat least one portion that is engageable with a component that cansupport the electronic device therefrom, the friction cylinder beingrotatable relative to the tilter body about the axis of rotation; abushing located between the friction cylinder and the opening of thetilter body, the bushing having a main portion, a first tab, a secondtab, and a split located between the first and second tabs, the mainportion having an exterior surface that engages the opening in thetilter body, an interior surface that engages the exterior surface ofthe friction cylinder, and an outer circumference, at least one of thefirst tab and second tab extending at least partially exterior to theouter circumference of the main portion of the bushing; and a threadedmember that is extendable through the threaded passage and into theopening of the tilter body such that the threaded member contacts one ofthe first tab and second tab.

Aspect 45. The tilter of Aspect 44, wherein at least a portion of eachof the first tab and the second tab extend exterior to the outercircumference of the main portion of the bushing.

Aspect 46. The tilter of either of Aspect 44 and Aspect 45, wherein anentirety of at least one of the first tab and the second tab extendsexterior to the outer circumference of the main portion of the bushing.

Aspect 47. The tilter of any of Aspects 44-46, the opening of the tilterbody comprising at least one seating surface located exterior to theouter circumference of the main portion of the bushing, wherein one ofthe first tab and second tab is in contact with the at least one seatingsurface.

Aspect 48. The tilter of any of Aspects 44-47, the opening of the tilterbody comprising a first seating surface and a second seating surface,the first and second seating surfaces located exterior to the outercircumference of the main portion of the bushing, wherein the first tabis in contact with the first seating surface and the second tab is incontact with the second seating surface, the interaction of the firsttab with the first seating surface and the interaction of the second tabwith the second seating surface preventing rotation of the bushingwithin the opening.

Aspect 49. The tilter of any of Aspects 44-48, the threaded membercomprising a shaft having a central axis, wherein the central axis doesnot extend through any portion of the outer circumference of the mainportion of the bushing when the threaded member is extended through thethreaded passage.

Aspect 50. The tilter of any of Aspects 44-49, the threaded membercomprising a shaft having a central axis, wherein the central axis isoriented at an orthogonal angle to the split in the bushing when theshaft is extended through the threaded passage.

Aspect 51. The tilter of any of Aspects 44-50, wherein the first tab andthe second tab have different dimensions.

Aspect 52. The tilter of any of Aspects 44-51, wherein the component isa center tilt mount that is fixedly engageable with the frictioncylinder such that the friction cylinder and the center tilt mount arecollectively rotatable relative to the tilter body about the axis ofrotation.

Aspect 53. The tilter of any of Aspects 44-52, wherein the bushing has awidth and the opening in the tilter body has a width, and the width ofthe bushing is at least 75% of the width of the opening.

Aspect 54. The tilter of any of Aspects 44-53, wherein the bushing has awidth and the opening in the tilter body has a width, and the width ofthe bushing is at least 90% of the width of the opening.

Aspect 55. The tilter of any of Aspects 44-54, wherein the bushing has awidth and the opening in the tilter body has a width, and the width ofthe bushing is equal to the width of the opening.

Aspect 56. The tilter of any of Aspects 44-55, wherein the bushing has awidth and the friction cylinder has a width, and the width of thebushing is at least 50% of the width of the friction cylinder.

Aspect 57. The tilter of Aspect 56, wherein the opening in the tilterbody has a width, and the width of the bushing is at least 75% of thewidth of the opening.

Aspect 58. The tilter of Aspect 56, wherein the opening in the tilterbody has a width, and the width of the bushing is at least 90% of thewidth of the opening.

Aspect 59. The tilter of Aspect 56, wherein the opening in the tilterbody has a width, and the width of the bushing is equal to the width ofthe opening.

Aspect 60. A tilter comprising: a tilter body, the tilter body having anopening and a passage located therein, the passage intersecting with theopening; a friction cylinder extending through the opening along an axisof rotation, the friction cylinder having an exterior surface and beingrotatable relative to the tilter body about the axis of rotation; abushing located between the friction cylinder and the opening of thetilter body, the bushing having a main portion, a first tab, a secondtab, and a split located between the first and second tabs, the mainportion having an exterior surface that engages the opening in thetilter body, an interior surface that engages the exterior surface ofthe friction cylinder, and an outer circumference, at least one of thefirst tab and the second tab extending at least partially exterior tothe outer circumference of the main portion of the bushing and the splitextending at least partially exterior to the outer circumference of themain portion of the bushing; and a pressure-supplying member that isextendable through the passage and into the opening of the tilter bodysuch that the pressure-supplying member contacts one of the first taband second tab.

Aspect 61. The tilter of Aspect 60, wherein the passage is threaded andthe pressure supplying-member is a threaded member.

The invention claimed is:
 1. A support arm for supporting an electronicdevice, the support arm comprising: a base portion that is adapted tosupport the support arm from a mounting surface; a lower arm portioncomprising a parallelogram portion, the parallelogram portion comprisingan upper channel, a lower channel, a lower endcap, and an upper endcap,wherein a first end of the upper channel and a first end of the lowerchannel are each rotatably attached to the lower endcap and a second endof the upper channel and a second end of the lower channel are eachrotatably attached to the upper endcap; a tilter assembly, the tilterassembly comprising a tilter body, a cylinder, and a center tilt mountthat is rotatably attached to the tilter body via the cylinder, thecenter tilt mount being adapted to support the electronic devicetherefrom; and at least one friction joint, the at least one frictionjoint comprising: a bushing comprising a main portion having an exteriorsurface, an interior surface, and an outer circumference, the bushingfurther comprising a first tab, a second tab, and a split locatedbetween the first and second tabs, wherein at least one of the first taband second tab extends at least partially exterior to the outercircumference of the main portion of the bushing; a friction cylindercomprising an exterior surface and at least one portion that fixedlyengages with a separate component of the support arm; an opening foraccommodating the bushing and friction cylinder therein; a threadedpassage that intersects with the opening; and a threaded member that isextendable through the threaded passage and into the opening, thebushing being located within the opening such that the exterior surfaceof the main portion of the bushing engages the opening, the frictioncylinder being located within the opening and routed internal to thebushing such that the exterior surface of the friction cylinder engagesthe interior surface of the main portion of the bushing, the frictioncylinder being rotatable along with the separate component of thesupport arm within the opening, the threaded member being extendableinto the opening such that the threaded member makes contact with one ofthe first tab and the second tab of the bushing, wherein the at leastone friction joint is located within at least one of the lower endcap,upper endcap, and tilter assembly, wherein if the at least one frictionjoint is located within either of the lower endcap and upper endcap, theseparate component is at least one of the upper channel and lowerchannel, and wherein if the at least one friction joint is locatedwithin the tilter assembly, the opening and threaded passage are locatedin the tilter body, the cylinder corresponds with the friction cylinder,and the separate component is the center tilt mount.
 2. The support armof claim 1, wherein a first friction joint of the at least one frictionjoint is located within the lower endcap and a second friction joint ofthe at least one friction joint is located within the tilter assembly.3. The support arm of claim 1, wherein at least a portion of each of thefirst tab and the second tab extend exterior to the outer circumferenceof the main portion of the bushing.
 4. The support arm of claim 3,wherein an entirety of at least one of the first tab and the second tabextends exterior to the outer circumference of the main portion of thebushing.
 5. The support arm of claim 1, the opening comprising at leastone seating surface located exterior to the outer circumference of themain portion of the bushing, wherein one of the first tab and second tabis in contact with the at least one seating surface.
 6. The support armof claim 1, the threaded member comprising a shaft having a centralaxis, wherein the central axis does not extend through any portion ofthe outer circumference of the main portion of the bushing when thethreaded member is extended through the threaded passage.
 7. The supportarm of claim 1, wherein the bushing has a width and the opening has awidth, and the width of the bushing is at least 75% of the width of theopening.
 8. The support arm of claim 1, wherein the bushing has a widthand the friction cylinder has a width, and the width of the bushing isat least 50% of the width of the friction cylinder.
 9. The support armof claim 8, wherein the opening has a width and the width of the bushingis at least 75% of the width of the opening.
 10. A support arm, thesupport arm comprising: a base portion that is adapted to support thesupport arm from a mounting surface; a lower arm portion comprising aparallelogram portion, the parallelogram portion comprising an upperchannel, a lower channel, a lower endcap, and an upper endcap, wherein afirst end of the upper channel and a first end of the lower channel arerotatably attached to the lower endcap and a second end of the upperchannel and a second end of the lower channel are rotatably attached tothe upper endcap; and a tilter assembly, the tilter assembly comprisinga tilter body, a friction cylinder, a bushing, and a threaded member,the tilter body having an opening and a threaded passage locatedtherein, the threaded passage intersecting with the opening, thefriction cylinder extending through the opening along an axis ofrotation, the friction cylinder having an exterior surface and at leastone portion that is engageable with a component that can support anelectronic device therefrom, the friction cylinder being rotatablerelative to the tilter body about the axis of rotation, the bushinglocated between the friction cylinder and the opening of the tilterbody, the bushing having a main portion, a first tab, a second tab, anda split located between the first and second tabs, the main portionhaving an exterior surface that engages the opening in the tilter body,an interior surface that engages the exterior surface of the frictioncylinder, and an outer circumference, at least one of the first tab andsecond tab extending at least partially exterior to the outercircumference of the main portion of the bushing, the threaded memberbeing extendable through the threaded passage and into the opening ofthe tilter body such that the threaded member contacts one of the firsttab and second tab.
 11. The support arm of claim 10, wherein at least aportion of each of the first tab and the second tab extend exterior tothe outer circumference of the main portion of the bushing.
 12. Thesupport arm of claim 10, wherein an entirety of at least one of thefirst tab and the second tab extends exterior to the outer circumferenceof the main portion of the bushing.
 13. The support arm of claim 10, theopening of the tilter body comprising at least one seating surfacelocated exterior to the outer circumference of the main portion of thebushing, wherein one of the first tab and second tab is in contact withthe at least one seating surface.
 14. The support arm of claim 10, thethreaded member comprising a shaft having a central axis, wherein thecentral axis does not extend through any portion of the outercircumference of the main portion of the bushing when the threadedmember is extended through the threaded passage.
 15. The support arm ofclaim 10, wherein the bushing has a width and the opening in the tilterbody has a width, and the width of the bushing is at least 75% of thewidth of the opening.
 16. The support arm of claim 10, wherein thebushing has a width and the friction cylinder has a width, and the widthof the bushing is at least 50% of the width of the friction cylinder.17. The support arm of claim 16, wherein the opening in the tilter bodyhas a width and the width of the bushing is at least 75% of the width ofthe opening.
 18. A support arm, the support arm comprising: a baseportion that is adapted to support the support arm from a mountingsurface; a lower arm portion comprising a parallelogram portion, theparallelogram portion comprising an upper channel, a lower channel, alower endcap, an upper endcap, and an extension and retraction device, afirst end of the upper channel being rotatably attached to the lowerendcap at a first joint, a first end of the lower channel beingrotatably attached to the lower endcap at a second joint, a second endof the upper channel being rotatably attached to the upper endcap at athird joint, and a second end of the lower channel being rotatablyattached to the upper endcap at a fourth joint, a first end of theextension and retraction device being attached to the lower endcap and asecond end of the extension retraction device being attached to thelower channel, wherein at least one of the first joint and the secondjoint comprises a friction joint, the lower endcap having a threadedpassage therein; and a device mount coupled to the lower arm portion,the device mount being adapted to support an electronic display devicetherefrom; wherein the friction joint comprises an opening located inthe lower endcap, a friction cylinder, a bushing, and a threaded member,the threaded passage intersects with the opening, the friction cylinderextends through the opening along an axis of rotation that correspondswith the respective one of the first joint and the second joint, thefriction cylinder having an exterior surface and at least one portionthat is engageable with the upper channel or lower channel, the frictioncylinder being rotatable relative to the lower endcap about the axis ofrotation, the bushing is located between the friction cylinder and theopening, the bushing having a main portion, a first tab, a second tab,and a split located between the first and second tabs, the main portionhaving an exterior surface that engages the opening in the lower endcap,an interior surface that engages the exterior surface of the frictioncylinder, and an outer circumference, at least one of the first tab andsecond tab extending at least partially exterior to the outercircumference of the main portion of the bushing, the threaded memberbeing extendable through the threaded passage and into the opening suchthat the threaded member contacts one of the first tab and second tab.19. The support arm of claim 18, wherein at least a portion of each ofthe first tab and the second tab extend exterior to the outercircumference of the main portion of the bushing.
 20. The support arm ofclaim 18, the threaded member comprising a shaft having a central axis,wherein the central axis does not extend through any portion of theouter circumference of the main portion of the bushing when the threadedmember is extended through the threaded passage.